Institut de recherche sur les lois fondamentales de l'Univers

Over the past decade, deep field surveys that probe well into the early age of the universe have dramatically improved our understanding of the formation and evolution of galaxies. The Cosmic Evolution Survey  (COSMOS) links the study of different galaxy populations to the large scale structure and environment utilizing a unique panchromatic dataset over the full electromagnetic spectrum. As part of COSMOS the largest radio continuum deep image at 20cm has been obtained. I will present highlights from the work using these unprecedented radio data and focus on a dust-unbiased view on star formation and the role played by radioactive galactic nuclei (AGN) in the evolution of galaxies.